Current methods for improving growth, nutrient utilization and disease resistance in animals rely on antibiotics, hormones and antimicrobials. The feed additives used for many decades and other processes for promoting animal growth and for improving nutrient utilization have had limited success and, the use of these substances is increasingly challenged worldwide. For example, antibiotics in feeds may not only lead to irreparable damage to animal health through the increasing formation of resistant pathogen strains with the danger of secondary diseases, but also may be dangerous to the health of humans, as the final consumers of foods of animal origin. The use of antibiotics in animals is blamed for the emergence of resistant strains of pathogens which pose a direct threat to man. Hormones may cause even greater damage to animal and human health, among other reasons, because of their anabolic promotion of the growth rate. The hormones may not be excreted from the animal body to the desired extent resulting in residues in edible tissues. Furthermore, antimicrobials can be carcinogenic or have co-carcinogenic effects on animals. As a result, many products used by farmers in the past to promote animal health, growth and nutrient utilization have been banned or subjected to curtailed application by government decree.
Since the usual products and processes show these numerous, health-damaging disadvantages and since no other suitable processes relating to commercially used feed are known, there is an increasing need for new methods and products to regulate digestion and improve growth, nutrient utilization and disease resistance in animals. Ideally these methods should be natural methods employing natural products that create no residues or adverse side effects. Moreover, a method should be effective in many types of species and in any age group. These methods should also be applicable to man for use in preventing malnutrition due to limited food supply, or to assist in recovery of debilitated patients.
Application of methods for improving nutrient utilization and regulating digestion have widespread implications. For example, when digestion is not properly stimulated, release of gastric enzymes and acids is diminished and the pH within the stomach is not sufficiently acidic to kill pathogenic microbes. Such microbes can cause a multitude of symptoms including colic, diarrhea, constipation and related diseases. These types of diseases have been observed in farm animals, especially pigs, because the acidity of fluids within the stomach typically reaches only about pH 5.6 to 5.7, whereas a pH of about 5.2-5.4 is needed to kill most pathogens (Kirchgessner et al. 1991 Zbl.f.Hygiene 191: 265-276). Currently, organic acids such as formic acid and citric acid are added to animal feed, especially pig feed, to lower the acidity of stomach fluids to the degree needed to kill pathogens. However, the presence of such organic acids in animal feed can have undesirable side effects. For example, use of such organic acids may cause or exacerbate gastric or intestinal ulcers. Therefore, new methods of stimulating normal digestive processes are urgently needed in the animal production industry.
Moreover, many other types of gastrointestinal disorders including ulcers and gastric erosions can occur as a result of improper regulation of digestive processes and could be prevented or treated if normal regulation of digestive processes could be reestablished. Such diseases represent a significant health problem worldwide. For example, approximately 8-10% of North Americans have recurring problems with peptic ulcers and total costs for treatment represent about 1% of national health care expenses in the United States. Moreover, the mortality rate of patients suffering from peptic ulcers has not decreased significantly since 1952, whereas mortality in women having gastric and duodenal ulcers has actually increased (Sonnenberg et al. 1983, Gastroenterology 84: 1553).
Some current methods of regulating digestion to treat ulcers rely on drugs like muscarinic and histamine H.sub.2 antagonists which are used to inhibit gastric acid secretion (Bauerfeind et al. 1986 Ulcustherapie JAMA 2: 135; Grossman, M. I. 1981, Regulation of gastric acid secretion. In: Physiology of the Gastrointestinal Tract, Ed. L. R. Johnson Raven Press, New York). However, these antagonists have undesirable side effects and frequently do not cure gastrointestinal disorders such as ulcers since many patients diagnosed as having ulcers and treated with these antagonists experience reoccurring symptoms within three years (DMW lll.Jg.Nr. 3, 1986).
Ulcers are a serious problem not only in human medicine but also in veterinary medicine, especially in pig, poultry, horse and cattle production, and in dogs and cats. For example, it is common for piglets to develop ulcers which can be lethal after weaning and a change to semi-liquid high energy diet. Within the European Common Market there are about 120,000,000 to 160,000,000 pigs raised annually and about the same number in North America.
Three to four percent are affected by severe ulcers which lead to death of the animal. Based upon these figures, about 4 million pigs per year are lost in Europe and in North America because of gastrointestinal disorders, resulting in a financial loss of up to 4 billion dollars per year. Similar losses occur in cattle and poultry farming as a result of gastrointestinal disease. Accordingly, there is an urgent need for new, safe and effective procedures to prevent and treat gastrointestinal diseases in both humans and animals.
Furthermore, there is a need for products and processes for increasing the growth rate and/or utilization of feeds and foods and/or resistance in animals and humans.